Author Topic: The Pinnacle of Dark Skies  (Read 284 times)

Mark

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The Pinnacle of Dark Skies
« on: July 25, 2017, 09:58:37 AM »
Saturday the 22nd of July I trekked to Pinnacles National Park to join what I assumed were a few members of the Santa Cruz Astronomy Club, along with my friend Richard Navarrete, for a night of dark sky astronomy. 

Getting there is easy, just heading down Highway 101, as if going to CalStar, into the Salinas Valley then turning east on Highway 146 at Soledad.  I used to visit that town returning from CalStar, whenever our event coincided with the Harvest Festival at the old Mission - a wonderful local celebration of food, wine, music, art and California history.

There is a turn on 146 in the vineyards, paralleling the valley, before heading off into to wilds, where the entire spread of Steinbeck's country shows itself.  The coastal range mountains to the east, containing the National Park, the broad flat fertile Salinas Valley covered now in vineyards, and across, past the town, past the Mission, the western part of the Coastal Range Mountains holding the Ventana Wilderness, and entrance to Big Sur.  It is a magnificent sight.  The road winds through a shallow canyon, in an area known for greasewood, Manzanita, grey pine, live and blue oak, buckeye, coffee berry, holly leaf cherry and elderberry.  During my drive in the park, I saw Turkey Vulture, Magpie, Roadrunner, Scrub Jay, Turkey, Quail (with many chick lets), Chipmunk, Ground Squirrel, Jack Rabbit and Cotton Tail Rabbit.

Entering the western part of Pinnacles is quite different from the eastern entrance, which I usually access for hiking (it’s a terrific park for hiking, in cooler spring and fall temps).  Just at the entrance, the Hoodoos welcome you, what a sight!  These are the western  remnants of  the ancient Neenach Volcano, last erupting 23 million years ago.  The eastern portion is 200 miles south near Lancaster, transported there by the San Andreas Fault, on which the park sits.

The observing site de la nuit was the parking lot by the ranger's station, just inside the park.  There was plenty of room and good horizons, especially to the south.  Once the skies darkened, I found it to be as dark as any sight I've been at within three hours of the Bay Area - to the sough it looked absolutely black, but nowhere was I disappointed with bothersome sky glow.

Richard and I brought our nearly identical 18" f/4.5 Obsession telescopes, planning to leave behind computers and work from paper charts (Sky Atlas 2000).  I observed mostly in Scorpius and Sagittarius, peeking into Pegasus late at night, with a few choice incursions into Cygnus for the fancy fun stuff there.

There were some park tourists visiting, looking through our telescopes.  I had one 11 year old girl describing views of the Bug Nebula, the more I asked her to look, the more detail she related.  It was great, and I know her parents (who had trouble seeing The Bug themselves) loved it.

Here are selected targets I observed:

NGC 6302, The Bug Nebula at 297X.
Bright, elongated E/W with a brighter section to the east.  A dark intrusion in the elongated western section leading to a bright knot 2/3rds of the way to the eastern end.  Approximately 1.5'x0.5', fading dramatically toward the eastern end.  Using an NPB filter, the object looks distinctly like a bi-polar planetary nebula, with the dimmer section and nucleus to the east.

NGC 6334, The Cat Paw Nebula at 200X with Ultrablock filter.
Faint nebulosity close to two bright fiend stars (mags 5.9 and 7.9) separated by 16 arc-minutes.  This view was probably hampered by poor seeing at the time.  The greatest portion of nebula, really just mottling in the field, was to the southeast of the stars.

NGC 6357, The Lobster Nebula, 200X with Ultrablock filter. 
Easy to locate at the straight eastern end of a chain of four mag 6 and one mag 7 stars, with one crookedly offset over 37 arc-minutes. The nebula runs N/S with uneven brightness, the most obvious portion is off the tip of the chain, and to the east.  More of the nebula runs from there north the to the west.  This is called a mini-M42.  Using 297X, clumpy nebulosity shows around dim stars in the chain, north to south, then a large clump east to west.

NGC 6990 and NGC 6995, Veil Nebula, 297X, NPB filter.
This was a mind-blowing view.  I knew it was a great night for the Veil when the Witch's Broom section showed tremendous detail.   I looked at this from Lick Observatory the prior weekend, and barely saw the tubular shape extending north of 52 Cygni.  At Pinnacles, there was so much to see, I kept moving my telescope wondering if what I was viewing was part of the Waterfall portion, but no, it was just very bright knots throughout the center, around Pickering's Wisp (or Pickering's Triangle).  When I finally moved enough to see the Waterfall (NGC 6995), it looked like stretched taffy, frozen, interwoven strands, bright knots mixed in with slivers and chards of "broken" pieces, leading to the delicate western turn where the "waterfall" drops off back toward the center of the Veil.  As I said, terrific, eye-popping view.

NGC 6888, Crescent Nebula, 297X, NPB filter.
After such a great view of the Veil Nebula, who could resist? So… wow. Beautiful view, the western edge to the north with the bright star embedded looked like smooth clay, thick and stretching and thinning to the south.  The nebulosity breaks, near the star close to the inner the western edge, getting thin and ragged as it turns toward the south where two bright knots show, at the curve eastward.  The eastern section is the thinnest, but a nice extension crosses the void to meet the bright star near the inner western edge.  Along the eastern edge, beyond the thin inner extension, is a brighter knot outside the oval, where the continuity of the "egg" shape seems to break.  Then it continues toward the north, brightening and thickening around two bright embedded stars, curving back over to join the northern end of the object.

Those were the highlight objects.  I also tried some tiny dim Planetaries, but the seeing was such that most stars were looking like Planetaries, so, too much work (NGC 6442 and IC 4732).  I popped a few small globulars, they're everywhere in this area, then finally jumped up into Pegasus for some NGC galaxies.

All in all, a fine night.  We had good company, and I have a new observing site that I look forward to returning to again just 1-1/2 hours from home.  But, new moons between now and then, an eclipse journey, and CalStar.

I also heard other observers and imagers were on the east side of the park, along with a star party that you weren't allow to bring scopes to (really????)!  Its certainly a world of wonders....

See you all soon.

Photos below: Entering Pinnacles West, early morning Hoodoos, fog in the Salinas Valley next morning, Crescent Nebula.
« Last Edit: July 25, 2017, 10:06:27 AM by Mark »

Mark

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Re: The Pinnacle of Dark Skies
« Reply #1 on: July 25, 2017, 11:23:30 AM »
I mentioned poor seeing.  When it was good, it was very very good.  When it was bad, it was horrid.

Transparency was also coming and going.  We had some unusual warm air currents invade the observing site for a while.  I think with those, the poor transparency arrived.

I think Pinnacles can be, and likely for those who go regularly is, a great place to observe.

John Pierce

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Re: The Pinnacle of Dark Skies
« Reply #2 on: July 25, 2017, 04:32:51 PM »
yeah, a bunch of us noticed that really warm air current around midnight or 1am, and I do think things deteriorated after that ....  I reverted to lower power things after that, and  about 1:30 or 2 I'd had enough and packed it in as Sunday was my wife's birthday and she wanted to go somewhere like SF for the day and if I'd come home at dawn, that wasn't going to happen.  as it was, getting home at 3am was bad enough.

Mark

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Re: The Pinnacle of Dark Skies
« Reply #3 on: July 25, 2017, 07:47:42 PM »
Smart choice going home.  It's really an easy drive.  I got some sleep in my car, setting the alarm for 6:30 to be gone before the rangers arrived.  I was something of a zombie on Sunday.
« Last Edit: July 26, 2017, 02:08:39 PM by Mark »

Brad

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Re: The Pinnacle of Dark Skies
« Reply #4 on: July 26, 2017, 01:12:38 PM »
Nice report! Hope to visit the Pinnacles some lovely, dark evening. Camping will probably limit me to the east side however.

Mark

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Re: The Pinnacle of Dark Skies
« Reply #5 on: August 05, 2017, 10:41:09 AM »
Hey Brad - stumbled across the picture today.  Surprise!  What year was it?